“In the case of two sisters who were given (in marriage) as a gift to two brothers and who in the night of going to bed with them each one went to bed with the woman of the other one, abu ‘Abd Allah (a.s.), has said, ‘Each one must pay mahr (dower) because of going to bed and if their guardians had known it and ignored they are liable for payment of mahr (dower). No one of them must go close to his wife until the waiting periods are complete, thereafter, each one can go to her husband according to the first marriage.’ He (the Imam) was asked, ’What happens if they both die before completion of waiting period?’ He (the Imam) said, ‘Their husbands demand for half of mahr (dower) from their (women’s) heir and both men have their shares in the legacy of the dead women.’ It was asked, ‘What happens if both men die and they are in their waiting period?’ He (the Imam) said, ‘They inherit them and they can have half of the mahr (dower) which was assigned and they must complete a waiting period after completing the waiting period before, the second being the waiting period for the death of their husbands.’”